Such a clamping device is described in DE 32,45,359 A1. The manner of clamping for the saw blade is unsatisfactory there, and it may lead to inaccurate cutting, especially in the case of different saw blade thicknesses. Even though a leaf spring is provided for pressing the saw blade, it cannot guarantee rigid, central guiding of the saw blades in the case of higher loads and different saw blade thicknesses. A slide is mounted in a slot of the housing as an adjusting member for releasing the saw blade. To release the saw blade, it is necessary to find the position in which the slide is able to release the saw blade from the centering sleeve. In addition, the point of clamping of the saw blade cannot be reached automatically. Actuating the slide is again necessary for this.
Clamping devices for saw blades of compass saws are described in U.S. Pat. No. 3,823,473. However, these are intended for saw blades different from those mentioned here, namely, for saw blades which are guided at holes. Positive-locking, accurate fit is not guaranteed there either in the case of saw blades of different thickness.
DE 30,06,299 A1 discloses a clamping device for a compass saw, in which the end of the saw blade can be tensioned or released by means of an adjusting member accessible from the outside at the plunger. Even though this makes it possible to replace the saw blade rapidly and without auxiliary tools, a displacement, which has an unfavorable effect on the precision of the sawcut, may develop between the longitudinal axis of the plunger and the longitudinal axis of the saw blade in the case of different saw blade thicknesses.
A clamping device for a compass saw is disclosed in DE 41,02,011 A1, which was not previously published. The precision of the sawcut is improved by a centering sleeve there, in which the clamped end of the compass sawing machine can be clamped by means of a clamping sleeve. The adjusting member is axially rigidly connected to the clamping sleeve, and is rotatable relative thereto. The adjusting member follows the sawcut and, if desired, in the case of an oscillating compass saw, also the oscillating movement. This is undesirable for the handling of the compass saw, and involves a certain risk of injury.
A one-part, spring-loaded centering pin, which supports the end zone of the clamped end of the saw blade, is mounted in the centering sleeve according to DE 41,02,011 A1. There inherently is a clearance between the centering pin and the centering sleeve. This leads to undesirable lateral movements of the saw blade. Such lateral movements diminish the precision of the sawcut.